xref: /openbmc/qemu/net/vhost-vdpa.c (revision 44602af8)
1 /*
2  * vhost-vdpa.c
3  *
4  * Copyright(c) 2017-2018 Intel Corporation.
5  * Copyright(c) 2020 Red Hat, Inc.
6  *
7  * This work is licensed under the terms of the GNU GPL, version 2 or later.
8  * See the COPYING file in the top-level directory.
9  *
10  */
11 
12 #include "qemu/osdep.h"
13 #include "clients.h"
14 #include "hw/virtio/virtio-net.h"
15 #include "net/vhost_net.h"
16 #include "net/vhost-vdpa.h"
17 #include "hw/virtio/vhost-vdpa.h"
18 #include "qemu/config-file.h"
19 #include "qemu/error-report.h"
20 #include "qemu/log.h"
21 #include "qemu/memalign.h"
22 #include "qemu/option.h"
23 #include "qapi/error.h"
24 #include <linux/vhost.h>
25 #include <sys/ioctl.h>
26 #include <err.h>
27 #include "standard-headers/linux/virtio_net.h"
28 #include "monitor/monitor.h"
29 #include "hw/virtio/vhost.h"
30 
31 /* Todo:need to add the multiqueue support here */
32 typedef struct VhostVDPAState {
33     NetClientState nc;
34     struct vhost_vdpa vhost_vdpa;
35     VHostNetState *vhost_net;
36 
37     /* Control commands shadow buffers */
38     void *cvq_cmd_out_buffer, *cvq_cmd_in_buffer;
39     bool started;
40 } VhostVDPAState;
41 
42 const int vdpa_feature_bits[] = {
43     VIRTIO_F_NOTIFY_ON_EMPTY,
44     VIRTIO_RING_F_INDIRECT_DESC,
45     VIRTIO_RING_F_EVENT_IDX,
46     VIRTIO_F_ANY_LAYOUT,
47     VIRTIO_F_VERSION_1,
48     VIRTIO_NET_F_CSUM,
49     VIRTIO_NET_F_GUEST_CSUM,
50     VIRTIO_NET_F_GSO,
51     VIRTIO_NET_F_GUEST_TSO4,
52     VIRTIO_NET_F_GUEST_TSO6,
53     VIRTIO_NET_F_GUEST_ECN,
54     VIRTIO_NET_F_GUEST_UFO,
55     VIRTIO_NET_F_HOST_TSO4,
56     VIRTIO_NET_F_HOST_TSO6,
57     VIRTIO_NET_F_HOST_ECN,
58     VIRTIO_NET_F_HOST_UFO,
59     VIRTIO_NET_F_MRG_RXBUF,
60     VIRTIO_NET_F_MTU,
61     VIRTIO_NET_F_CTRL_RX,
62     VIRTIO_NET_F_CTRL_RX_EXTRA,
63     VIRTIO_NET_F_CTRL_VLAN,
64     VIRTIO_NET_F_GUEST_ANNOUNCE,
65     VIRTIO_NET_F_CTRL_MAC_ADDR,
66     VIRTIO_NET_F_RSS,
67     VIRTIO_NET_F_MQ,
68     VIRTIO_NET_F_CTRL_VQ,
69     VIRTIO_F_IOMMU_PLATFORM,
70     VIRTIO_F_RING_PACKED,
71     VIRTIO_NET_F_RSS,
72     VIRTIO_NET_F_HASH_REPORT,
73     VIRTIO_NET_F_GUEST_ANNOUNCE,
74     VIRTIO_NET_F_STATUS,
75     VHOST_INVALID_FEATURE_BIT
76 };
77 
78 /** Supported device specific feature bits with SVQ */
79 static const uint64_t vdpa_svq_device_features =
80     BIT_ULL(VIRTIO_NET_F_CSUM) |
81     BIT_ULL(VIRTIO_NET_F_GUEST_CSUM) |
82     BIT_ULL(VIRTIO_NET_F_MTU) |
83     BIT_ULL(VIRTIO_NET_F_MAC) |
84     BIT_ULL(VIRTIO_NET_F_GUEST_TSO4) |
85     BIT_ULL(VIRTIO_NET_F_GUEST_TSO6) |
86     BIT_ULL(VIRTIO_NET_F_GUEST_ECN) |
87     BIT_ULL(VIRTIO_NET_F_GUEST_UFO) |
88     BIT_ULL(VIRTIO_NET_F_HOST_TSO4) |
89     BIT_ULL(VIRTIO_NET_F_HOST_TSO6) |
90     BIT_ULL(VIRTIO_NET_F_HOST_ECN) |
91     BIT_ULL(VIRTIO_NET_F_HOST_UFO) |
92     BIT_ULL(VIRTIO_NET_F_MRG_RXBUF) |
93     BIT_ULL(VIRTIO_NET_F_STATUS) |
94     BIT_ULL(VIRTIO_NET_F_CTRL_VQ) |
95     BIT_ULL(VIRTIO_F_ANY_LAYOUT) |
96     BIT_ULL(VIRTIO_NET_F_CTRL_MAC_ADDR) |
97     BIT_ULL(VIRTIO_NET_F_RSC_EXT) |
98     BIT_ULL(VIRTIO_NET_F_STANDBY);
99 
100 VHostNetState *vhost_vdpa_get_vhost_net(NetClientState *nc)
101 {
102     VhostVDPAState *s = DO_UPCAST(VhostVDPAState, nc, nc);
103     assert(nc->info->type == NET_CLIENT_DRIVER_VHOST_VDPA);
104     return s->vhost_net;
105 }
106 
107 static int vhost_vdpa_net_check_device_id(struct vhost_net *net)
108 {
109     uint32_t device_id;
110     int ret;
111     struct vhost_dev *hdev;
112 
113     hdev = (struct vhost_dev *)&net->dev;
114     ret = hdev->vhost_ops->vhost_get_device_id(hdev, &device_id);
115     if (device_id != VIRTIO_ID_NET) {
116         return -ENOTSUP;
117     }
118     return ret;
119 }
120 
121 static int vhost_vdpa_add(NetClientState *ncs, void *be,
122                           int queue_pair_index, int nvqs)
123 {
124     VhostNetOptions options;
125     struct vhost_net *net = NULL;
126     VhostVDPAState *s;
127     int ret;
128 
129     options.backend_type = VHOST_BACKEND_TYPE_VDPA;
130     assert(ncs->info->type == NET_CLIENT_DRIVER_VHOST_VDPA);
131     s = DO_UPCAST(VhostVDPAState, nc, ncs);
132     options.net_backend = ncs;
133     options.opaque      = be;
134     options.busyloop_timeout = 0;
135     options.nvqs = nvqs;
136 
137     net = vhost_net_init(&options);
138     if (!net) {
139         error_report("failed to init vhost_net for queue");
140         goto err_init;
141     }
142     s->vhost_net = net;
143     ret = vhost_vdpa_net_check_device_id(net);
144     if (ret) {
145         goto err_check;
146     }
147     return 0;
148 err_check:
149     vhost_net_cleanup(net);
150     g_free(net);
151 err_init:
152     return -1;
153 }
154 
155 static void vhost_vdpa_cleanup(NetClientState *nc)
156 {
157     VhostVDPAState *s = DO_UPCAST(VhostVDPAState, nc, nc);
158     struct vhost_dev *dev = &s->vhost_net->dev;
159 
160     qemu_vfree(s->cvq_cmd_out_buffer);
161     qemu_vfree(s->cvq_cmd_in_buffer);
162     if (dev->vq_index + dev->nvqs == dev->vq_index_end) {
163         g_clear_pointer(&s->vhost_vdpa.iova_tree, vhost_iova_tree_delete);
164     }
165     if (s->vhost_net) {
166         vhost_net_cleanup(s->vhost_net);
167         g_free(s->vhost_net);
168         s->vhost_net = NULL;
169     }
170      if (s->vhost_vdpa.device_fd >= 0) {
171         qemu_close(s->vhost_vdpa.device_fd);
172         s->vhost_vdpa.device_fd = -1;
173     }
174 }
175 
176 static bool vhost_vdpa_has_vnet_hdr(NetClientState *nc)
177 {
178     assert(nc->info->type == NET_CLIENT_DRIVER_VHOST_VDPA);
179 
180     return true;
181 }
182 
183 static bool vhost_vdpa_has_ufo(NetClientState *nc)
184 {
185     assert(nc->info->type == NET_CLIENT_DRIVER_VHOST_VDPA);
186     VhostVDPAState *s = DO_UPCAST(VhostVDPAState, nc, nc);
187     uint64_t features = 0;
188     features |= (1ULL << VIRTIO_NET_F_HOST_UFO);
189     features = vhost_net_get_features(s->vhost_net, features);
190     return !!(features & (1ULL << VIRTIO_NET_F_HOST_UFO));
191 
192 }
193 
194 static bool vhost_vdpa_check_peer_type(NetClientState *nc, ObjectClass *oc,
195                                        Error **errp)
196 {
197     const char *driver = object_class_get_name(oc);
198 
199     if (!g_str_has_prefix(driver, "virtio-net-")) {
200         error_setg(errp, "vhost-vdpa requires frontend driver virtio-net-*");
201         return false;
202     }
203 
204     return true;
205 }
206 
207 /** Dummy receive in case qemu falls back to userland tap networking */
208 static ssize_t vhost_vdpa_receive(NetClientState *nc, const uint8_t *buf,
209                                   size_t size)
210 {
211     return 0;
212 }
213 
214 static NetClientInfo net_vhost_vdpa_info = {
215         .type = NET_CLIENT_DRIVER_VHOST_VDPA,
216         .size = sizeof(VhostVDPAState),
217         .receive = vhost_vdpa_receive,
218         .cleanup = vhost_vdpa_cleanup,
219         .has_vnet_hdr = vhost_vdpa_has_vnet_hdr,
220         .has_ufo = vhost_vdpa_has_ufo,
221         .check_peer_type = vhost_vdpa_check_peer_type,
222 };
223 
224 static void vhost_vdpa_cvq_unmap_buf(struct vhost_vdpa *v, void *addr)
225 {
226     VhostIOVATree *tree = v->iova_tree;
227     DMAMap needle = {
228         /*
229          * No need to specify size or to look for more translations since
230          * this contiguous chunk was allocated by us.
231          */
232         .translated_addr = (hwaddr)(uintptr_t)addr,
233     };
234     const DMAMap *map = vhost_iova_tree_find_iova(tree, &needle);
235     int r;
236 
237     if (unlikely(!map)) {
238         error_report("Cannot locate expected map");
239         return;
240     }
241 
242     r = vhost_vdpa_dma_unmap(v, map->iova, map->size + 1);
243     if (unlikely(r != 0)) {
244         error_report("Device cannot unmap: %s(%d)", g_strerror(r), r);
245     }
246 
247     vhost_iova_tree_remove(tree, map);
248 }
249 
250 static size_t vhost_vdpa_net_cvq_cmd_len(void)
251 {
252     /*
253      * MAC_TABLE_SET is the ctrl command that produces the longer out buffer.
254      * In buffer is always 1 byte, so it should fit here
255      */
256     return sizeof(struct virtio_net_ctrl_hdr) +
257            2 * sizeof(struct virtio_net_ctrl_mac) +
258            MAC_TABLE_ENTRIES * ETH_ALEN;
259 }
260 
261 static size_t vhost_vdpa_net_cvq_cmd_page_len(void)
262 {
263     return ROUND_UP(vhost_vdpa_net_cvq_cmd_len(), qemu_real_host_page_size());
264 }
265 
266 /** Copy and map a guest buffer. */
267 static bool vhost_vdpa_cvq_map_buf(struct vhost_vdpa *v,
268                                    const struct iovec *out_data,
269                                    size_t out_num, size_t data_len, void *buf,
270                                    size_t *written, bool write)
271 {
272     DMAMap map = {};
273     int r;
274 
275     if (unlikely(!data_len)) {
276         qemu_log_mask(LOG_GUEST_ERROR, "%s: invalid legnth of %s buffer\n",
277                       __func__, write ? "in" : "out");
278         return false;
279     }
280 
281     *written = iov_to_buf(out_data, out_num, 0, buf, data_len);
282     map.translated_addr = (hwaddr)(uintptr_t)buf;
283     map.size = vhost_vdpa_net_cvq_cmd_page_len() - 1;
284     map.perm = write ? IOMMU_RW : IOMMU_RO,
285     r = vhost_iova_tree_map_alloc(v->iova_tree, &map);
286     if (unlikely(r != IOVA_OK)) {
287         error_report("Cannot map injected element");
288         return false;
289     }
290 
291     r = vhost_vdpa_dma_map(v, map.iova, vhost_vdpa_net_cvq_cmd_page_len(), buf,
292                            !write);
293     if (unlikely(r < 0)) {
294         goto dma_map_err;
295     }
296 
297     return true;
298 
299 dma_map_err:
300     vhost_iova_tree_remove(v->iova_tree, &map);
301     return false;
302 }
303 
304 /**
305  * Copy the guest element into a dedicated buffer suitable to be sent to NIC
306  *
307  * @iov: [0] is the out buffer, [1] is the in one
308  */
309 static bool vhost_vdpa_net_cvq_map_elem(VhostVDPAState *s,
310                                         VirtQueueElement *elem,
311                                         struct iovec *iov)
312 {
313     size_t in_copied;
314     bool ok;
315 
316     iov[0].iov_base = s->cvq_cmd_out_buffer;
317     ok = vhost_vdpa_cvq_map_buf(&s->vhost_vdpa, elem->out_sg, elem->out_num,
318                                 vhost_vdpa_net_cvq_cmd_len(), iov[0].iov_base,
319                                 &iov[0].iov_len, false);
320     if (unlikely(!ok)) {
321         return false;
322     }
323 
324     iov[1].iov_base = s->cvq_cmd_in_buffer;
325     ok = vhost_vdpa_cvq_map_buf(&s->vhost_vdpa, NULL, 0,
326                                 sizeof(virtio_net_ctrl_ack), iov[1].iov_base,
327                                 &in_copied, true);
328     if (unlikely(!ok)) {
329         vhost_vdpa_cvq_unmap_buf(&s->vhost_vdpa, s->cvq_cmd_out_buffer);
330         return false;
331     }
332 
333     iov[1].iov_len = sizeof(virtio_net_ctrl_ack);
334     return true;
335 }
336 
337 /**
338  * Do not forward commands not supported by SVQ. Otherwise, the device could
339  * accept it and qemu would not know how to update the device model.
340  */
341 static bool vhost_vdpa_net_cvq_validate_cmd(const struct iovec *out,
342                                             size_t out_num)
343 {
344     struct virtio_net_ctrl_hdr ctrl;
345     size_t n;
346 
347     n = iov_to_buf(out, out_num, 0, &ctrl, sizeof(ctrl));
348     if (unlikely(n < sizeof(ctrl))) {
349         qemu_log_mask(LOG_GUEST_ERROR,
350                       "%s: invalid legnth of out buffer %zu\n", __func__, n);
351         return false;
352     }
353 
354     switch (ctrl.class) {
355     case VIRTIO_NET_CTRL_MAC:
356         switch (ctrl.cmd) {
357         case VIRTIO_NET_CTRL_MAC_ADDR_SET:
358             return true;
359         default:
360             qemu_log_mask(LOG_GUEST_ERROR, "%s: invalid mac cmd %u\n",
361                           __func__, ctrl.cmd);
362         };
363         break;
364     default:
365         qemu_log_mask(LOG_GUEST_ERROR, "%s: invalid control class %u\n",
366                       __func__, ctrl.class);
367     };
368 
369     return false;
370 }
371 
372 /**
373  * Validate and copy control virtqueue commands.
374  *
375  * Following QEMU guidelines, we offer a copy of the buffers to the device to
376  * prevent TOCTOU bugs.
377  */
378 static int vhost_vdpa_net_handle_ctrl_avail(VhostShadowVirtqueue *svq,
379                                             VirtQueueElement *elem,
380                                             void *opaque)
381 {
382     VhostVDPAState *s = opaque;
383     size_t in_len, dev_written;
384     virtio_net_ctrl_ack status = VIRTIO_NET_ERR;
385     /* out and in buffers sent to the device */
386     struct iovec dev_buffers[2] = {
387         { .iov_base = s->cvq_cmd_out_buffer },
388         { .iov_base = s->cvq_cmd_in_buffer },
389     };
390     /* in buffer used for device model */
391     const struct iovec in = {
392         .iov_base = &status,
393         .iov_len = sizeof(status),
394     };
395     int r = -EINVAL;
396     bool ok;
397 
398     ok = vhost_vdpa_net_cvq_map_elem(s, elem, dev_buffers);
399     if (unlikely(!ok)) {
400         goto out;
401     }
402 
403     ok = vhost_vdpa_net_cvq_validate_cmd(&dev_buffers[0], 1);
404     if (unlikely(!ok)) {
405         goto out;
406     }
407 
408     r = vhost_svq_add(svq, &dev_buffers[0], 1, &dev_buffers[1], 1, elem);
409     if (unlikely(r != 0)) {
410         if (unlikely(r == -ENOSPC)) {
411             qemu_log_mask(LOG_GUEST_ERROR, "%s: No space on device queue\n",
412                           __func__);
413         }
414         goto out;
415     }
416 
417     /*
418      * We can poll here since we've had BQL from the time we sent the
419      * descriptor. Also, we need to take the answer before SVQ pulls by itself,
420      * when BQL is released
421      */
422     dev_written = vhost_svq_poll(svq);
423     if (unlikely(dev_written < sizeof(status))) {
424         error_report("Insufficient written data (%zu)", dev_written);
425         goto out;
426     }
427 
428     memcpy(&status, dev_buffers[1].iov_base, sizeof(status));
429     if (status != VIRTIO_NET_OK) {
430         goto out;
431     }
432 
433     status = VIRTIO_NET_ERR;
434     virtio_net_handle_ctrl_iov(svq->vdev, &in, 1, dev_buffers, 1);
435     if (status != VIRTIO_NET_OK) {
436         error_report("Bad CVQ processing in model");
437     }
438 
439 out:
440     in_len = iov_from_buf(elem->in_sg, elem->in_num, 0, &status,
441                           sizeof(status));
442     if (unlikely(in_len < sizeof(status))) {
443         error_report("Bad device CVQ written length");
444     }
445     vhost_svq_push_elem(svq, elem, MIN(in_len, sizeof(status)));
446     g_free(elem);
447     if (dev_buffers[0].iov_base) {
448         vhost_vdpa_cvq_unmap_buf(&s->vhost_vdpa, dev_buffers[0].iov_base);
449     }
450     if (dev_buffers[1].iov_base) {
451         vhost_vdpa_cvq_unmap_buf(&s->vhost_vdpa, dev_buffers[1].iov_base);
452     }
453     return r;
454 }
455 
456 static const VhostShadowVirtqueueOps vhost_vdpa_net_svq_ops = {
457     .avail_handler = vhost_vdpa_net_handle_ctrl_avail,
458 };
459 
460 static NetClientState *net_vhost_vdpa_init(NetClientState *peer,
461                                            const char *device,
462                                            const char *name,
463                                            int vdpa_device_fd,
464                                            int queue_pair_index,
465                                            int nvqs,
466                                            bool is_datapath,
467                                            bool svq,
468                                            VhostIOVATree *iova_tree)
469 {
470     NetClientState *nc = NULL;
471     VhostVDPAState *s;
472     int ret = 0;
473     assert(name);
474     if (is_datapath) {
475         nc = qemu_new_net_client(&net_vhost_vdpa_info, peer, device,
476                                  name);
477     } else {
478         nc = qemu_new_net_control_client(&net_vhost_vdpa_info, peer,
479                                          device, name);
480     }
481     snprintf(nc->info_str, sizeof(nc->info_str), TYPE_VHOST_VDPA);
482     s = DO_UPCAST(VhostVDPAState, nc, nc);
483 
484     s->vhost_vdpa.device_fd = vdpa_device_fd;
485     s->vhost_vdpa.index = queue_pair_index;
486     s->vhost_vdpa.shadow_vqs_enabled = svq;
487     s->vhost_vdpa.iova_tree = iova_tree;
488     if (!is_datapath) {
489         s->cvq_cmd_out_buffer = qemu_memalign(qemu_real_host_page_size(),
490                                             vhost_vdpa_net_cvq_cmd_page_len());
491         memset(s->cvq_cmd_out_buffer, 0, vhost_vdpa_net_cvq_cmd_page_len());
492         s->cvq_cmd_in_buffer = qemu_memalign(qemu_real_host_page_size(),
493                                             vhost_vdpa_net_cvq_cmd_page_len());
494         memset(s->cvq_cmd_in_buffer, 0, vhost_vdpa_net_cvq_cmd_page_len());
495 
496         s->vhost_vdpa.shadow_vq_ops = &vhost_vdpa_net_svq_ops;
497         s->vhost_vdpa.shadow_vq_ops_opaque = s;
498         error_setg(&s->vhost_vdpa.migration_blocker,
499                    "Migration disabled: vhost-vdpa uses CVQ.");
500     }
501     ret = vhost_vdpa_add(nc, (void *)&s->vhost_vdpa, queue_pair_index, nvqs);
502     if (ret) {
503         qemu_del_net_client(nc);
504         return NULL;
505     }
506     return nc;
507 }
508 
509 static int vhost_vdpa_get_iova_range(int fd,
510                                      struct vhost_vdpa_iova_range *iova_range)
511 {
512     int ret = ioctl(fd, VHOST_VDPA_GET_IOVA_RANGE, iova_range);
513 
514     return ret < 0 ? -errno : 0;
515 }
516 
517 static int vhost_vdpa_get_features(int fd, uint64_t *features, Error **errp)
518 {
519     int ret = ioctl(fd, VHOST_GET_FEATURES, features);
520     if (unlikely(ret < 0)) {
521         error_setg_errno(errp, errno,
522                          "Fail to query features from vhost-vDPA device");
523     }
524     return ret;
525 }
526 
527 static int vhost_vdpa_get_max_queue_pairs(int fd, uint64_t features,
528                                           int *has_cvq, Error **errp)
529 {
530     unsigned long config_size = offsetof(struct vhost_vdpa_config, buf);
531     g_autofree struct vhost_vdpa_config *config = NULL;
532     __virtio16 *max_queue_pairs;
533     int ret;
534 
535     if (features & (1 << VIRTIO_NET_F_CTRL_VQ)) {
536         *has_cvq = 1;
537     } else {
538         *has_cvq = 0;
539     }
540 
541     if (features & (1 << VIRTIO_NET_F_MQ)) {
542         config = g_malloc0(config_size + sizeof(*max_queue_pairs));
543         config->off = offsetof(struct virtio_net_config, max_virtqueue_pairs);
544         config->len = sizeof(*max_queue_pairs);
545 
546         ret = ioctl(fd, VHOST_VDPA_GET_CONFIG, config);
547         if (ret) {
548             error_setg(errp, "Fail to get config from vhost-vDPA device");
549             return -ret;
550         }
551 
552         max_queue_pairs = (__virtio16 *)&config->buf;
553 
554         return lduw_le_p(max_queue_pairs);
555     }
556 
557     return 1;
558 }
559 
560 int net_init_vhost_vdpa(const Netdev *netdev, const char *name,
561                         NetClientState *peer, Error **errp)
562 {
563     const NetdevVhostVDPAOptions *opts;
564     uint64_t features;
565     int vdpa_device_fd;
566     g_autofree NetClientState **ncs = NULL;
567     g_autoptr(VhostIOVATree) iova_tree = NULL;
568     NetClientState *nc;
569     int queue_pairs, r, i, has_cvq = 0;
570 
571     assert(netdev->type == NET_CLIENT_DRIVER_VHOST_VDPA);
572     opts = &netdev->u.vhost_vdpa;
573     if (!opts->vhostdev) {
574         error_setg(errp, "vdpa character device not specified with vhostdev");
575         return -1;
576     }
577 
578     vdpa_device_fd = qemu_open(opts->vhostdev, O_RDWR, errp);
579     if (vdpa_device_fd == -1) {
580         return -errno;
581     }
582 
583     r = vhost_vdpa_get_features(vdpa_device_fd, &features, errp);
584     if (unlikely(r < 0)) {
585         return r;
586     }
587 
588     queue_pairs = vhost_vdpa_get_max_queue_pairs(vdpa_device_fd, features,
589                                                  &has_cvq, errp);
590     if (queue_pairs < 0) {
591         qemu_close(vdpa_device_fd);
592         return queue_pairs;
593     }
594 
595     if (opts->x_svq) {
596         struct vhost_vdpa_iova_range iova_range;
597 
598         uint64_t invalid_dev_features =
599             features & ~vdpa_svq_device_features &
600             /* Transport are all accepted at this point */
601             ~MAKE_64BIT_MASK(VIRTIO_TRANSPORT_F_START,
602                              VIRTIO_TRANSPORT_F_END - VIRTIO_TRANSPORT_F_START);
603 
604         if (invalid_dev_features) {
605             error_setg(errp, "vdpa svq does not work with features 0x%" PRIx64,
606                        invalid_dev_features);
607             goto err_svq;
608         }
609 
610         vhost_vdpa_get_iova_range(vdpa_device_fd, &iova_range);
611         iova_tree = vhost_iova_tree_new(iova_range.first, iova_range.last);
612     }
613 
614     ncs = g_malloc0(sizeof(*ncs) * queue_pairs);
615 
616     for (i = 0; i < queue_pairs; i++) {
617         ncs[i] = net_vhost_vdpa_init(peer, TYPE_VHOST_VDPA, name,
618                                      vdpa_device_fd, i, 2, true, opts->x_svq,
619                                      iova_tree);
620         if (!ncs[i])
621             goto err;
622     }
623 
624     if (has_cvq) {
625         nc = net_vhost_vdpa_init(peer, TYPE_VHOST_VDPA, name,
626                                  vdpa_device_fd, i, 1, false,
627                                  opts->x_svq, iova_tree);
628         if (!nc)
629             goto err;
630     }
631 
632     /* iova_tree ownership belongs to last NetClientState */
633     g_steal_pointer(&iova_tree);
634     return 0;
635 
636 err:
637     if (i) {
638         for (i--; i >= 0; i--) {
639             qemu_del_net_client(ncs[i]);
640         }
641     }
642 
643 err_svq:
644     qemu_close(vdpa_device_fd);
645 
646     return -1;
647 }
648